1. Field of the Invention
The present invention relates generally to stereotactic breast biopsy systems and more particularly to an adapter assembly suitable for use in a stereotactic breast biopsy system to support a biopsy device.
2. Description of the Related Art
Stereotactic breast biopsy systems are a precise, minimally invasive diagnostic tool for use in performing fine-needle aspiration and needle core biopsies of the human breast to determine whether a breast lesion is benign or malignant. Needle biopsies, unlike more invasive surgical procedures, are typically performed on an out-patient basis with local anesthesia. Stereotactic breast biopsy systems generally include an ergonomically contoured table that comfortably supports the patient in a stable, fixed position that exposes the patient's breast. Stereotactic breast biopsy systems also generally include a diagnostic imaging system for targeting the lesion to be biopsied. The location of the target lesion is used by a guidance system to guide insertion of the biopsy needle into the patient's breast tissue.
The biopsy needle used in a stereotactic breast biopsy is typically a component of a biopsy device, which is supported by the guidance system in an appropriate adapter. Recently there has been developed an improved biopsy device that includes a cutting element mounted to a handpiece. The cutting element includes an outer cannula defining a tissue receiving opening and an inner cannula concentrically disposed within the outer cannula and connected to the handpiece. An outer cannula hub is removably mounted to the handpiece and is connected to the outer cannula. The outer cannula hub allows removal of the handpiece and inner cannula from the outer cannula, leaving the outer cannula in position within the patient's breast tissue to serve as an introducer for biopsy site markers and therapeutics.
During a biopsy procedure it is desirable that the cutting element be accurately positioned adjacent the lesion and remain there throughout the procedure. While conventional adapters selectively inhibit rotation of the biopsy device, once the device is removed, they do not maintain registration with the biopsy site along the Z-axis, i.e., the axis that extends into and out of the patient's body. It is also desirable that the outer cannula, particularly the tissue receiving opening, remain in registration with the biopsy site after removal of the handpiece and inner cannula. Conventional adapters are unequipped to handle removal of the handpiece and inner cannula from the outer cannula, let alone maintain consistent registration between the outer cannula and the biopsy site after removal of the handpiece and inner cannula.
Accordingly, an improved stereotactic adapter is required that facilitates removal of the handpiece and inner cannula, while leaving the outer cannula in position to serve as an introducer for biopsy site markers and therapeutics. An improved stereotactic adapter is also required that maintains consistent registration of the outer cannula with the biopsy site throughout a biopsy procedure, even after removal of the handpiece and inner cannula.